Variable Side Look Concept for Radar Mapping of Planetary Surfaces

Planetary mapping by side looking synthetic aperture radar overcomes the problems of imaging through cloud covers. Circular orbits simplify the radar operation and are, by far, the outstanding choice where possible. In cases where the velocity requirements at the planet are large and put a strain on spacecraft propulsion systems, mapping from elliptic orbits has been considered. This mapping mode requires innovative operational and design aspects of the radar system. The purpose of this paper is to present an approach to mapping planetary surfaces from elliptic orbits with synthetic aperture radar systems. The applications to Venus have been investigated as representative.